That's great thanks, but they are not just power amplifier, at first I dismissed them because they were not just power amplifier, and it still bothers me having a useless knob, but after taking a deeper look there is a bypass volume to disable pre-amp which is great.3e Audio A5, A7 and A7 Mono are 2 ohm stable, A5se and A7se only go up to 4 ohm.
No 12v trigger like NC502MP offering, but both Fosi and 3e Audio supports automatic detection through input voltage right ?
Any one of those TPA3255 will be enough to drive annoying 2.5 Ohms speakers without any reliability and stability issue ?